Influence of Relative Humidity on Mechanical Properties of Alumina, PZT and Zirconia

The fracture toughness of different types of alumina, PZT and magnesium partially stabilized zirconia is investigated at different humidities and loading rates at room temperature using a four-point SENB set-up. It is revealed that the fracture toughness decreases with increasing humidity. However, a sharp decrease in fracture toughness is observed below 2-10 percent humidity. From 10 percent relative humidity onwards the fracture toughness remains constant. (Author)